Chitosan-Based Molecularly Imprinted Polymer Modified Zinc Oxyde/Graphene Nanocomposite/Screen Printed Carbon Electrode for Electrochemical Detection of Methyl Paraben

Abstract

A novel electrochemical sensor, chitosan based on molecularly imprinted polymer (MIP), was fabricated by electrodeposition of chitosan in the presence of methyl paraben (MP) on a zinc oxide/graphene nanocomposite (ZnO/GnC) modified screen-printed carbon electrode for selective detection of MP. The obtained chitosan-based MIP modified electrode, namely MIP/ZnO/GnC/SPCE was characterized by scanning electron microscopy, cyclic voltammetry, and differential pulse voltammetry. Under the optimized condition, the prepared sensor MIP/ZnO/GnC/SPCE exhibited satisfactory linearity with certain MP concentrations of 10 to 1000 μM and the limit of detection can reach 9.65 μM with a sensitivity of 0.00445 μA/μM.cm2. This work shows that the incorporation of chitosan-based MIP with ZnO/GnC generates a synergistic effect, increasing the current response in comparison with unmodified SPCE. The developed sensor exhibited satisfactory reproducibility and repeatability. Furthermore, the developed electrode was successfully applied for the determination of MP in cosmetic products and shows similar performance in comparison to UV-visible spectrophotometry analysis. In conclusion, the chitosan-based MIP modified ZnO/GnC/SPCE is promising for monitoring the MP in cosmetic products.